Recipe(tried): Bechamel Lasagna with Sausage, Mushrooms and Spinach

This is the lasagna that went into the freezer this afternoon. It's a recipe I came up with, combining a friend's recipe, (previous post:"Leslie Woodard's Lasagna") and the Bechamel Sauce recipe (tripled) from the cookbook, Vegetables, by James Peterson

BECHAMEL LASAGNA WITH SAUSAGE,
MUSHROOMS AND SPINACH

FOR THE BECHAMEL SAUCE:
6 Tablespoons butter
1 small onion, finely chopped
7 1/2 Tablespoons flour
4 cups evaporated skim milk
2 cups skim milk
1 bay leaf, broken in two
1 small pinch ground nutmeg
salt and pepper to taste
FOR THE LASAGNA:
1 lb. lasagna noodles
4 Tablespoons olive oil
2 garlic cloves
1 small onion, chopped
1/2 pound mushrooms, sliced
1/2 lb. Italian Sausage
1 lb. ground round
Salt and pepper to taste
1/2 cup grated Parmesan cheese
1 pkg. frozen chopped spinach, thawed, drained and liquid squeezed out
1 1/2 cups Mozzarella

TO MAKE THE BECHAMEL SAUCE:
Melt the butter in a heavy-bottomed saucepan over medium heat. Add the onions and stir for about 10 minutes until they smell fragrant.

Stir in the flour and continue to cook, while stirring with a wooden spoon, until the flour smells toasty, about 5 minutes.

Whisk in half the milk and bring to a simmer while whisking continually. When the milk has reached a boil and the sauce is smooth, add the rest of the milk, the nutmeg and the bay leaf, and bring to a gentle simmer. Reduce heat to low and simmer for 15 minutes.

Season to taste with salt and pepper and strain. Cover sauce with plastic wrap, pressing down so wrap touches the sauce (this will keep a skin from forming while you prepare the lasagna); reserve.

TO MAKE THE LASAGNA:
Preheat oven to 350 degrees F.

Drop noodles in boiling water that some olive oil has been added to. Boil 2 minutes. Drain. Lay noodles out flat.

Brown garlic, onions, mushrooms, sausage & ground round in olive oil in order given. Add 2 tablespoons of the Parmesan cheese. Mix well.

Pour 1/2 cup bechamel sauce in bottom of large baking dish that has been sprayed with cooking spray. Place a layer of noodles on the sauce followed by a layer of Parmesan, a layer of sausage mixture, half the spinach, and a layer of mozzarella. Repeat until all cheese, sausage mixture and spinach are used. Top layers should be noodles, b chamel sauce and grated cheese, in that order.

Cover tightly with foil and bake 45 minutes or until hot and bubbly. Let sit 15 minutes before cutting.